As Marketers, we’re all laser-focused on improving the quality of our email campaigns, working hard to provide relevant and timely content to ever-more-carefully segmented constituencies.

But all of this effort is for naught whenever one of our perfectly-timed and highly-tailored emails ends up in our intended recipient’s junk folder.

Sometimes it is the invisible things that matter — one can’t see deliverability, but if it’s neglected it will dramatically impact the effectiveness of our campaigns at every level.

Prefer to print this out?

Get the PDF

If it Goes in the SPAM Folder, it Never Happened


Job One is to understand your lists – maintaining high standards of “list health” is an integral part of any successful email marketing campaign. Do you acquire new lists from a list vendor? Have you been sending to the same list for an extended period of time? Are you dusting off an old list that you haven’t used in a while?

Following these tips will help you get rid of bad email addresses and disengaged recipients, helping you improve both your engagement rates and your sender reputation.

  1. Send to Your Most Engaged First. Separate out your most engaged recipients and schedule a send to those groups first. These individuals will provide you with high open and click through rates. High performance on an initial send will “prime” your campaigns and often results in improved overall delivery and inbox rates.
  2. Honor Unsubscribes Quickly. When an unsubscribe request is received for a recipient, that recipient must be suppressed within 10 business days. Neglecting this dramatically reduces your chances of winning the recipient back, and is a violation of CAN-SPAM, CASL and other state Spam laws, and can result in lawsuits and fines.
  3. Clean-up Non-Engaged Recipients. Regularly (e.g. monthly) separate out 12-month non-engaged recipients. As an example, if you send one message per week to a recipient for 12 months, that recipient would have received a total of 48 messages. If he/she didn’t open or click in any of them, that would be a non-engaged recipient who is very unlikely to open or click in the future. That email address could even be a spam trap.Non-engaged recipients can be placed in a special list group that can be used for future re-engagement campaigns. We can help with rolling out these types of campaigns in a way that will minimize sender/IP reputation damage.
  4. Set up bounce suppression campaigns that automatically remove addresses that bounce consistently for the same reason (e.g. bad domain, mailbox full, generic hard/soft). This can help to improve and maintain your overall list health, sender reputation, ROI, and keep delivery and inbox rates high, all while reducing your overall email costs.
  5. Use List Hygiene Services. If you need to send to an “old” list, say one that you haven’t emailed in over six months, or a purchased/rented list, it’s best to have that list cleaned by a list hygiene service like Fresh Address to remove as many addresses as possible that are:
    • Undeliverable
    • Spam Traps, or addresses that are deliverable but potentially damaging to your reputation
    • Individuals who often loudly complain about Spam email

With enough volume, these types of addresses can seriously damage your sender reputation and the reputation of your IPs, and potentially cause serious blacklistings on your IPs or sending domain.


Best practices in email marketing constantly evolve to reflect ever-changing online behavior. It’s important to stay current with the latest email protocols in order to optimize campaign effectiveness and maintain the most positive relationship with your campaign recipients.

The following is an updated list of things that you might consider avoiding when creating and sending your email messages. Staying away from these “Don’ts” will help you make a more positive impact in your recipients’ inboxes.


  • Link to “executable” files like .exe, .zip, .swf, etc. This is likely to cause your messages to get marked as a “phishing” email by spam filters, and placed in the Spam folder or even quarantined.
  • Use JavaScript in your content. Most email clients will block JavaScript or strip out that code entirely. As a result, your email may not display as intended and could even be placed in the Spam folder or quarantined.
  • Link to external stylesheets – most email clients will block them.
  • Use loud colors in the email body text, such as pure red or green. This can come across as “yelling” at your recipients, trying to attract their attention to an area of your message, which is something spammers tend to do.
  • Use all capital letters in the subject line or overuse them in the body of the message (same reason as above).
  • Use exclamation signs or other punctuation marks more than once (same reason as above).
  • Use excessive symbols – use descriptive words instead. When you use dollar signs, make sure you don’t overdo it ($$$).
  • Use the word “test” in the subject line, or “dummy” text, like Lorem Ipsum, in the body of the message, even when sending a preliminary version of your message for review. Both could cause your message to go to the Spam folder.

  • Use spammy words or phrases unnecessarily, like “mortgage”, “act now!”, “click here!”, “limited time”, and “guaranteed”.

  • Get “creative” with your spelling, like “FR33”, “m0rtgage”, “MON3Y”, etc., especially in the subject line. Spammers do this to try and trick Spam filters, so they’re programmed to look for them.

  • Use “corporate” or “official” phrases in your unsubscribe links, like “…to stop further distribution”, or “To prevent future messages from being sent…”. That type of phrase could end up triggering Spam filters. And an unsubscribe link that says anything like “…you registered with a partner” will greatly increase your chances of going into the Spam folder because it’s an indication that your list isn’t permission based.

  • Use the word “Dear” when addressing your recipients, as in “Dear Reader” or “Dear Mary”. This will increase your Spam score.

  • Display full URLs in the body of the HTML version of the message. Instead, use a text string like “visit our website” that includes the HTML link underneath it in an anchor tag.

  • Link to “executable” files like .exe, .zip, .swf, etc. This is likely to cause your messages to get marked as a “phishing” email by spam filters, and placed in the Spam folder or even quarantined.
  • Use a domain in your message content that’s blacklisted. You can use a site like to check whether a domain is on a blacklist.
  • Use ‘Re’ or ‘Fwd’ in the subject line to trick recipients into thinking that your mail is a continuation of a previous conversation. NOTE: Using a misleading subject line is a violation of CAN-SPAM and other Spam laws.

  • Offer misleading or unsubstantiated claims in the subject line or message.

  • Use bad/broken HTML coding in email. You can validate your code online with the authority on HTML here:
  • Convert Microsoft Word files to HTML – even the best conversion tools could miss some of Microsoft’s proprietary or hidden tags, which could cause your messages to be displayed incorrectly, or even get them mistaken as a phishing message or placed in the Spam folder.
  • Use a single, large image in your message. This practice is used by spammers to hide their content from Spam filters. Aim for 60% or more text and 40% or less images, and break larger images up into at least two smaller images.


  • Include a “Friendly From’ label along with your ‘From’ address. For example “Jim’s Online Hardware”<>. Messages from unknown/unrecognized senders are more likely to be reported as spam.
  • Use your company’s domain in your ‘From’ address, and authenticate your messages (SPF/DKIM/DMARC) with your company’s domain as well. This will make your messages more recognizable to Spam filters and your recipients, give your messages legitimacy, and greatly reduce the chance that they will be seen as a phishing attempt.
  • Include your physical mailing address and phone number in every message.
  • Provide an unsubscribe link within every message that’s relatively easy for your recipients to find. This could help to reduce Spam complaints, and is required by most Spam laws. The unsubscribe link must be active within at least 60 days of sending the email.
    NOTE: Failure to include an unsubscribe link and/or honor unsubscribe requests within 10 business days is a violation of CAN-SPAM, CASL and other Spam laws.
  • Use opt-in/permission-based marketing techniques to avoid sending to unknown/invalid addresses, and getting excessive spam complaints and unsubscribes. If you feel like you must rent or purchase addresses, be sure to use a legitimate and reputable source, and have the list cleaned by a list hygiene service to remove invalid/undeliverable addresses, spam trap addresses, throw-away addresses, etc.
  • Keep your message size under 100kb, especially for recipients who read messages on a mobile device. That’s not a hard and fast size limit, just a reasonable target to shoot for.
  • Use the same/similar text in both the HTML and Text versions of your messages. Spam filters look for this.
  • Ensure that the design of your email templates clearly identifies your brand and/or website. Prominently display your logo/brand and/or company name, and use your website’s color scheme so that your recipients immediately recognize who they’re from.
  • Use a ‘Friendly From’ label, ‘From’ address, and subject line that clearly and immediately identify you as the sender. This will help improve your open, read, and click-through rates, and reduce spam complaints and unsubscribes.
  • NOTE: Failure to clearly identify the sender of a message is a violation of CAN-SPAM, CASL and other Spam laws.
  • Ensure that all the images in your message have alternative (alt) text in the image tag so that something descriptive is displayed in their place when they’re not rendered.
  • Use inline styles as much as possible, e.g. style="font-size: 18px; font-family: Arial, sans-serif; color: #333333;". Some email clients, like Gmail, will strip the head, body andstyle tags from your messages. Using inline styles ensures that the styling in your messages is displayed as you intend in these clients.

Implementing these tips is not only critical in terms of getting your messages through Spam filters, but it will organically help improve your relationship with your recipients, as well.